/* 
 * Copyright (c) 2004-2005 Massachusetts Institute of Technology. This code was
 * developed as part of the Haystack (http://haystack.lcs.mit.edu/) research 
 * project at MIT. Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation files (the 
 * "Software"), to deal in the Software without restriction, including without 
 * limitation the rights to use, copy, modify, merge, publish, distribute, 
 * sublicense, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions: 
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER  
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. 
 */
/*
 * Created on Sep 6, 2004
 *
 */
package jiggle.relo;

import java.util.Collection;
import java.util.Set;
import java.util.Map.Entry;

import jiggle.AbstractForceLaw;
import jiggle.Cell;
import jiggle.Graph;

import org.eclipse.draw2d.geometry.Point;

/**
 *  
 * @author vineet
 *  
 */
public class SpringAnchoredFrictionLaw extends AbstractForceLaw {

    private final Set<Entry<Cell, Collection<Point>>> anchorMap;
    private final AbstractForceLaw attrLaw;

    public SpringAnchoredFrictionLaw(Graph g, double edgeLength, Set<Entry<Cell, Collection<Point>>> anchorMap, AbstractForceLaw attrLaw) {
        super(g, edgeLength);
        this.anchorMap = anchorMap;
        this.attrLaw = attrLaw;
    }

    @Override
    public double pairwiseWeights (double pref, double curr) {
        return attrLaw.pairwiseWeights(pref, curr) / 4;
    }

    @Override
    public void apply(double[][] negativeGradient) {
        for (Entry<Cell, Collection<Point>> anchorEntry : anchorMap) {
            Cell anchorCell = anchorEntry.getKey();
            for (Point anchorPoint : anchorEntry.getValue()) {
                applyForCellCoord(negativeGradient, anchorCell, new double[] {anchorPoint.x, anchorPoint.y}, 1);
            }
        }
    }

}